If you want
a quick sling on thing rather than layering up which can take an age, go to hein gerike and have a gander at their top of the range jackets - Master V, etc. The insulation in that keeps me quite comfortable at a windchill of -21C. Obviously this is combined with the jacket being well constructed to keep holes sealed and a decent windproof layer but if you can find the same sort of thinsulate at the same weight they use, you'll be fine.
As for warmth, get some muffs for £30, after that any non vented gloves will do you - summer gloves, perhaps not. Heated grips are a bonus - if you get oxford muffs you can buy their heated over grips and insert them into the muffs (don't use them as grips as they just fall apart) to create heated muffs. Instructions are supplied with muffs.
If you have a good budget and you want to ride all through winter, you'll have to state how much you're willing to spend and we'll be able to advise. Also, if you pay £100 for a jacket, you'll replace it every year and it'll be adequate. If you pay £500 for a jacket it'll last you five years and be fantastic (as long as you wash and re-waterproof it occasionally). It's a matter of if you have the capital to buy the quality kit outright.
Boots - look at Ride tests - TCX infinity boots (i think) are good.
Neck / hat cold = scarf. I use an old scrim scarf and it's perfect as it traps air and insulates as well as being mashable into the various gaps around your hat. The other thing is a new product from oxford which is like the Foggy - it covers nose and mouth to stop misting and also gives you a bit of a chin curtain as well.
Just remember if you're commuting them you'll not want to be wrapping up like a bloody space man every time you set off. Layer on layer works but it takes ages so look at minimising layers and maximising effectiveness, unless you've plenty of time on your hands.